Keying system capable of producing piano-tone effects for use in electronic musical instruments

Claim 2

A keying system for an electronic musical instrument having a number of playing keys, comprising, per key: a percussive pulse generating circuit associated with each individual key for generating a percussive electrical pulse in response to the operation of its respectively associated key; a voltage divider circuit including serially connected voltage dropping elements connected to each of said percussive pulse generating circuits for delivering a plurality of electrical percussive pulses of respectively different amplitudes; and a plurality of tone keyers for respectively keying tone signals of different frequencies, which keyers are respectively connected to said voltage dropping elements to effect correspondingly respective control by the respective percussive pulses of different amplitude delivered from said voltage divider circuit, the higher amplitude pulses controlling the keyers for the lower frequency tone signals.

Claim 3

A keying system according to claim 1, in which said voltage dropping elements comprise at least one resistor and a plurality of diodes.

Claim 4

A keying system according to claim 1, in which said voltage dropping elements comprise all resistors.

Claim 5

A keying system according to claim 1, in which said percussive pulse generating circuit includes means for generating said percussive electrical pulse having a peak amplitude responsive to the depressing speed of said associated key.

Claim 6

A keying system according to claim 1, in which said percussive pulse generating circuit includes means for generating said percussive electrical pulse as a constant pulse waveform regardless of the depressing speed of said playing key.

Claim 7

A keying system according to claim 1, in which said tone keyers associated with a key are four in number and which include means for producing an 8-foot, a 4-foot, a 2 2/3 -foot and a 2-foot register tone signal, respectively.

Claim 8

A keying system according to claim 1, in which said tone keyers associated with a key are four in number and which include means for producing an 8-foot, a first 4-foot and a 2-foot register tone signal and a second 4-foot register tone signal which is derived from other tone generator than said first 4-foot register tone signal, respectively.

Claim 9

In a keying system for an electronic musical instrument having a number of playing keys and a percussive signal generator, an improvement for more accurately generating percussion tonal effects with tone color approximating that of a true percussion instrument, said improvement comprising: a voltage divider means having an input connected to said percussive signal generator to receive a percussive electrical pulse shaped to approximate the general amplitude rise-time and decay-time characteristics of percussion generated sounds in response to the actuation of a playing key, said voltage divider means having plural outputs for providing a plurality of control pulses corresponding in shape to said percussive electrical pulse, but with each succeeding control pulse being successively reduced in amplitude from the preceding one, a corresponding plurality of tone keyer means, each connected to key tone signals of predetermined frequencies in response to a corresponding one of said control pulses which are respectively connected thereto for causing the lower frequency tone signals to be keyed by the higher amplitude control pulses whereby the higher frequency keyed tones decay more quickly than the lower frequency keyed tones thereby more closely approximating the tone color characteristics of a true percussion instrument.

Claim 10

In a keying system for an electronic musical instrument having a number of playing keys and a percussive signal generator, an improvement for more accurately generating percussion tonal effects with tone color approximating that of a true percussion instrument, said improvement comprising: a voltage divider means having an input connected to said percussive signal generator to receive a percussive electrical pulse shaped to approximate the general amplitude rise-time and decay-time characteristics of percussion generated sounds in response to the actuation of a playing key, said voltage divider means having plural outputs for providing a plurality of control pulses corresponding in shape to said percussive electrical pulse, but with each succeeding control pulse being successively reduced in amplitude from the preceding one, a corresponding plurality of tone keyer means, each connected to key tone signals of predetermined frequencies in response to a corresponding one of said control pulses which are respectively connected thereto for causing the lower frequency tone signals to be keyed by the higher amplitude control pulses whereby the higher frequency keyed tones decay more quickly than the lower frequency keyed tones thereby more closely approximating the tone color characteristics of a true percussion instrument.

Claim 11

An improvement as in claim 8 wherein said voltage divider means includes both resistive and diode elements.

Claim 12

An improvement as in claim 8 wherein said voltage divider means comprises all resistive elements.

Claim 13

An improvement as in claim 8 wherein outputs of a plurality of tone keyer means are electrically connected in common for mixing the keyed tone signals.

Claim 14

An improvement as in claim 8 wherein at least one voltage divider means output is connected by diodes to control more than one tone keyer means.